September is National Bourbon Heritage Month, and it’s always interesting to brush up on the history of this American classic. The first thing you need to know is that for whiskey to be considered bourbon, it has to meet certain qualifications.

The main requirements are that it must be made from a grain mixture that contains at least 51% corn, be distilled to no more than 160 proof, be aged in charred, new American oak barrels, and be made in the USA.

Whiskey making was popular amongst early American settlers, and Kentucky became an important hub for production in the 18th and 19th centuries. Unlike in Europe, corn was abundant in the New World, and it soon became a staple for distillation. Bourbon County, which was named after the French Bourbon Dynasty, gave this unique American product its name.

Here are some other fun facts:

1. In 1964, Congress recognized bourbon as a “distinctive product of the United States.”
2. 95% of all bourbon is made in Kentucky, but it can be produced anywhere in the United States
3. Bourbon cannot enter a barrel any higher than 125 proof.
4. Bourbon must be bottled at a minimum of 80 proof.
5. Bourbon must be aged in new charred oak barrels.
6. Bourbon has no minimum aging requirement, but to be labeled “straight bourbon,” the product must be aged at least two years. Any bourbon aged less than four years must include an age statement on the label.
7. Unlike rum and certain other spirits, a bourbon’s stated age must be that of the youngest whiskey in the bottle.
8. There are more bourbon barrels in Kentucky than there are people.